New Study Shows Increased Brain Activity in Depressed Individuals during Visuospatial Memory Tasks
A new study published in Psychiatry Research: Neuroimaging has revealed that individuals with high depression scores exhibit heightened brain activity in frontal brain regions while performing visuospatial memory tasks, despite having similar behavioral performance to those with low depression scores.
Depression is often associated with emotional aspects, but it can also affect cognitive abilities such as memory, attention, and decision-making. Structural and functional changes in the brain have been observed in individuals with depression, particularly in areas like the prefrontal cortex and the amygdala.
Previous studies have yielded conflicting results concerning the impact of depression on test scores measuring cognitive abilities and brain activity during these tests. To address these inconsistencies in the literature, researchers Özge Vural Keleş from Bartin University and Erol Yıldırım from Istanbul Medipol University in Turkey conducted a study to clarify the relationship between depression and visuospatial working memory.
The study involved 501 volunteer university students and graduates who completed the Beck Depression Inventory online to assess their depression symptoms. Participants with the lowest and highest scores on the inventory were then invited to the laboratory for further experiments.
The study comprised 23 individuals with high depression scores (average BDI ≥ 23) and 20 individuals with low depression scores (average BDI ≤ 11), with similar age and education levels across groups. All participants completed a visuospatial 2-back working memory task to measure their working memory performance.
During the task, participants were shown a series of images or words and asked to remember the location of these stimuli within a circular display. They had to determine whether the current stimulus matched the one presented two steps back in the sequence. Brain responses were recorded using functional near-infrared spectroscopy (fNIRS), a brain imaging technique that monitors changes in blood flow and oxygen levels to identify active brain areas.
Statistical analyses revealed no significant behavioral differences between the high and low depression groups in the visuospatial working memory task. However, fNIRS showed that individuals with high depression scores exhibited increased activation in the right dorsolateral prefrontal cortex compared to the low depression group.
The researchers concluded that the high depression group put in more effort in the right prefrontal cortex to achieve the same performance as the low depression group. They referred to this increased activation as a compensatory effort.
The study has some limitations, including the lack of an official clinical diagnosis in the high depression group, which may affect the validity of the findings. Additionally, the low difficulty of the visuospatial working memory task could have contributed to similar scores in both the high and low depression groups.
The authors of the study, Özge Vural Keleş and Erol Yıldırım, hope that their findings contribute to a better understanding of the impact of depression on cognitive abilities and brain functioning.
The study, titled “Depression affects working memory performance: A Functional Near Infrared Spectroscopy (fNIRS) Study,” provides valuable insights into the relationship between depression and visuospatial memory tasks.